Actuator modules generally include a driving device (a motor) and a reduction gear and are widely used for general industrial use as well as for home and educational use. Specifically, that a plurality of actuator modules may be coupled to materialize an articulated robot capable of performing complicated operations has been receiving more attention lately.
FIG. 1 is an actual photograph illustrating a humanoid type articulated robot which is implemented by coupling standardized actuator modules and connection members thereof (see Korean Patent Application Publication No. 10-2013-0018402). In such a robot, each of the actuator modules should be controlled according to a predetermined rule, and through such control, each of the actuator modules drives another actuator module or a module connection member such that various operations can be realized. For example, a humanoid type articulated robot should realize various operations simulating human actions.
FIG. 2 illustrates a state in which an actuator module (at a lower side) and a module connection member (at an upper side) are coupled to each other. A plurality of actuator modules are necessarily connected to module connection members on the basis of an active shaft of each of a plurality of actuator modules, and a coupling structure between the plurality of actuator modules and the module connection members is repeated such that a robot having a form shown in FIG. 1, or having a desired shape can be manufactured.
In most cases, one side of an actuator module is an active side and the other side thereof is a passive side. When a hinge type joint is used, a shaft configured to receive a driving force from a motor is installed at one side of an actuator module, and an idler horn configured to serve as a support member, which does not transfer the driving force, is installed at the other side of the actuator module. Unlike an active shaft, an idler horn is frequently attached and detached due to various reasons. For example, the idler horn needs to be detached due to damage to the idler horn, replacement of a tube-shaped bearing for a rotational movement of the idler horn, or the like. Therefore, a structure in which the idler horn can be conveniently attached and detached is required.
Wire arrangement is important in connecting an actuator module to a module connection member or another actuator module. Specifically, when a plurality of actuator modules are controlled by a central processing unit or a central controller, a plurality of wires for controlling and sensing are required, and the arrangement of these wires should not interfere with the driving of each of the plurality of actuator modules. Further, when the wires are complicatedly entangled, an exterior is poor. Furthermore, when the number of actuator modules constituting a robot increases, difficulty of wire arrangement becomes more serious such that problems may occur in which a driving range of an actuator is limited, a structure of the robot cannot be varied, and the like. In the past, there were attempts to implement a hollow type small-sized modular actuator, but due to limitations of an inner diameter of a bearing, there was an inconvenience in that cables needed to be passed through a hole first without a connector and were then assembled with the connector again, and a limitation in that maintenance was difficult when issues occurred.
In order to resolve such problems, the idler horn should be made to have a hollow structure and the cables should be connected to an interior of a housing through the hollow, and in this case, the need for attaching and detaching the hollow-type idler horn in order to connect the cables is even greater.